Hot Topics:

Philadelphia Zoo lets tigers stretch legs on trail

Amur tigers walk across a passageway after a new conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (AP Photo/Matt Slocum)

PHILADELPHIA (AP) — Beware of stray cats at the Philadelphia Zoo.A new enclosed passageway called Big Cat Crossing allows visitors to safely watch as lions and tigers roam outside their habitats.The protected, open-air path was unveiled Wednesday. It's part of an effort to enrich the experience of both creatures and guests.The 100-yard-long trail snakes above the cat exhibit. Visitors can watch the sleek felines cross an archway over the zoo's main promenade to a viewing spot at a lake.The zoo already has separate trails winding through its property for large apes and small primates. Officials say the campus-wide system is unique among zoos in the U.S.Big Cat Crossing will be in regular use starting Saturday.